Gamma Gruis

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Gamma Gruis
Template:Location mark
Location of γ Gruis (circled) near the center
Observation data
Epoch J2000      Equinox J2000
Constellation Grus
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) 3.003[2]
Characteristics
Spectral type B8 III[3] or B8IV-Vs[4]
U−B Template:Engvar −0.307[2]
B−V Template:Engvar −0.121[2]
Astrometry
Radial velocity (Rv)−2.1[5] km/s
Proper motion (μ) RA: +98.07[1] mas/yr
Dec.: −13.22[1] mas/yr
Parallax (π)15.45±0.67 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−1.05[6]
Details
Mass3.06[7] Template:Solar mass
Radius4.5[8] Template:Solar radius
Luminosity373[6] Template:Solar luminosity
Surface gravity (log g)3.79[7] cgs
Temperature12,520[9] K
Rotation4.987[10] d
Rotational velocity (v sin i)57[11] km/s
Age75[7] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist[12]
Database references
SIMBADdata

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Gamma Gruis or γ Gruis, formally named Aldhanab (Template:IPAc-en),[13] is a star in the southern constellation of Grus (it once belonged to the Ptolemaic constellation Piscis Austrinus). With an apparent visual magnitude of 3.0,[2] it is the third-brightest star in Grus. Based upon parallax measurements, this star is located at a distance of roughly Template:Convert from the Sun.[1]

Nomenclature

γ Gruis (Latinised to Gamma Gruis) is the system's Bayer designation.

It bore the traditional Arabic name Al Dhanab, from the Arabic الذنب al-dhanab "the tail" (of the Southern Fish)[14]when it was still part of Piscis Austrinus with the Bayer designation κ Piscis Austrini (Kappa Piscis Austrini). In 2016, the IAU organized a Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN approved the name Aldhanab for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[13]

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Decayed Mortar, refers to an asterism consisting of Gamma Gruis, Lambda Gruis, Gamma Piscis Austrini and 19 Piscis Austrini.[16] Consequently, the Chinese name for Gamma Gruis itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx.)[17]

Properties

Analysis of the spectrum by N. Houk in 1979 shows it to match a stellar classification of B8 III,[3] with the luminosity class of III indicating this is a giant star that has exhausted the supply of hydrogen at its core and evolved away from the main sequence. R. O. Gray and R. F. Garrison in 1989 found a less evolved class of B8IV-Vs.[4] The luminosity of Gamma Gruis is around 390 times that of the Sun, with a significant portion of the energy emission being in the ultraviolet.[18] Its outer envelope has an effective temperature of 12,520 K,[9] which gives the star a blue-white hue. Gamma Gruis is rotating relatively rapidly with a projected rotational velocity of 57 km s−1.[11] By way of comparison, the Sun has an azimuthal velocity along its equator of just 2 km s−1.

Based upon analysis of data collected during the Hipparcos mission, this star may have a proper motion companion that is causing gravitational perturbation of Gamma Gruis.[19] In addition, there is a star sharing common proper motion and similar distance with Gamma Gruis, and thus is believed to the gravitationally bound. It has a projected separation of Template:Convert, and a mass and radius around 30% that of the Sun. They likely make a binary system.[20]

See also

References

Template:Reflist

Template:Stars of Grus

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  1. ↑ a b c d e f Cite error: Invalid <ref> tag; no text was provided for refs named aaa474_2_653
  2. ↑ a b c d Cite error: Invalid <ref> tag; no text was provided for refs named sps1966
  3. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named houk1979
  4. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named Gray_Garrison_1989
  5. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named gcsrv
  6. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named Anderson2012
  7. ↑ a b c Cite error: Invalid <ref> tag; no text was provided for refs named David2015
  8. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named mnras189_601
  9. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa501_1_297
  10. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Barraza
  11. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa393_3_897
  12. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named SIMBAD
  13. ↑ a b Script error: No such module "citation/CS1".
  14. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named allen1963
  15. ↑ Script error: No such module "citation/CS1".
  16. ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
  17. ↑ Template:In lang AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 5 日 Template:Webarchive
  18. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named kaler
  19. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named aaa464_1_377
  20. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Kervella2022
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